Cytoprotective activity of carrot and tomato callus extracts and the ex‐ pression of cytokines in UV‐B irradiated fibroblast cells

Studies have suggested that both carrot ( Daucus carota L.) and tomato ( Solanum lycopersicum L.) callus extracts contain antoxidant compounds that might have the potental to protect cells from free radicals such as H 2 O 2 that contribute to cell damage. The other sources of free radical exposure in human cells, such as UV‐B, should also be examined. UV‐B exposure can trigger increased expression of inflammatory cytokines such as cyclooxygenase‐2 (COX‐2) and tumor necrosis factor‐α (TNF‐α) and the antinflammatory cytokine interleukin‐10 (IL‐10), which causes photoaging. This study was conducted to investgate the cytoprotectve actvity of carrot and tomato callus aqueous extracts by observing cell viability using the MTT assay. Immunocytochemistry methods were used to examine the effects of carrot and tomato callus aqueous extracts on the expression of COX‐2, TNF‐α, and IL‐10 in human dermal fbroblast adult (HDFa) cells exposed to UV‐B light. Carrot and tomato callus aqueous extracts were obtained by the maceraton method using aqua bidistlled solvent. Results showed that both carrot and tomato callus aqueous extracts at 0.5 mg/mL exhibited the highest cytoprotectve effect in HDFa cells compared to that at other concentratons. Both carrot and tomato callus aqueous extracts could also decrease the expression of COX‐2 and TNF‐α, whereas carrot callus aqueous extract increased the expression of the ant‐inflammatory cytokine IL‐10 in HDFa cells.